WO2008113248A1 - Flange with cooling groove, pipeline with said flange and connecting method therefor - Google Patents

Abstract

A flange is disclosed in the invention. A cooling groove (4) is provided on the sealing surface (8) of said flange. At least a cooling hole (9) is provided at the rear (6) of the flange. Said cooling hole (9) connects with the cooling groove (4) by penetrating through the flange. The flange in the invention is applied onto the antisepsis of various connectors of metal pipes with eroding medium. A pipeline with said flange and a connecting method therefor are also disclosed in the invention. The method of connecting pipelines could prevent from destroying the inner antiseptic layer of the pipeline when heat being produced due to welding, so as to ensure the integrity of said inner antiseptic layer of the pipeline to further ensure that the entire pipeline has excellent antiseptic performance.

Description

 Flange with cooling groove, pipe with the flange and its connection method ■ Technical field

 The present invention relates to a flange, and more particularly to a flange that facilitates cooling during the welding process, a pipe with the flange, and a method of joining the pipe. Background technique

 Metal pipes are widely used due to their good mechanical properties and mature manufacturing processes. However, the corrosion of metal pipes, especially the corrosion of pipe joints, has not been effectively solved. For the construction of steel pipelines, the method of butt welding is used. The pipe joint connected by this method has good performance, low cost, simple operation and good sealing performance. However, the joint welding temperature is up to more than one thousand degrees. The inner anti-corrosion layer of the pipe in the welded joint is usually damaged. The weld is a green pipe. The whole pipe with internal anti-corrosion layer often forms a large cathode. The anode accelerates pipe corrosion. Therefore, if the area where the 'anti-corrosion layer is damaged around the weld and the weld is not treated, it will be preferentially corroded during use, resulting in loss of leakage and stoppage.

 At present, there is still a lack of effective equipment and methods for post-weld internal filling. Especially for the sprayed porcelain pipes that can be buried in the underground for 50 years and the plastic coated steel pipes with strong corrosion resistance, the protection of welded joints has always been the main factor restricting its promotion and application. Summary of the invention

 In order to overcome the deficiencies in the prior art, it is an object of the present invention to provide a flange which has good strength and sealing ability and which is convenient to be cooled while being welded by welding to protect the inner coating, and thus is suitable for various types. Welding pipes, such as oil and gas pipes.

 An aspect of the invention provides a flange having a cooling groove on a sealing surface and at least one cooling hole on a back surface of the flange, the cooling hole penetrating the flange and cooling The slots are connected.

 In a preferred embodiment, the cooling groove forms a curved shape such as a circle, a spiral or the like around the center hole of the flange, preferably circular.

In another preferred embodiment, the cross-sectional shape of the cooling trough is any geometric shape such as semi-circular, rectangular, semi-elliptical, preferably semi-circular. In some preferred embodiments, the sealing surface of the flange may be in the form of a flat, concave-convex, grooved or ring-connected surface.

 In other preferred embodiments, the outer edge of the sealing surface of the flange is provided with a groove.

 In a particular embodiment of the invention, the flange is selected from the group consisting of a neck butt weld flange, a neck flat weld flange, a plate flat weld flange, an integral flange or other type of flange.

 Since the flange of the invention has a cooling groove, the conduction of heat to the inner wall of the flange can be weakened when the joint is welded, thereby avoiding the damage of the anti-corrosion layer in the pipeline by the heat input during welding, thereby ensuring the integrity of the anti-corrosion layer in the pipeline, Ensure that the pipeline as a whole has good corrosion resistance.

 Another aspect of the invention provides a pipe with a flange of the invention.

 In a preferred embodiment, the inner surface of the pipe is coated with a corrosion resistant inner coating.

 A further aspect of the invention also provides a method of joining the conduit of the invention, comprising the steps of:

 (1) coaxially butt the sealing faces of the flanges of the two pipes to be connected, and apply adhesive at the sealing faces for bonding;

 (2) injecting cooling fluid into the cooling tank through the cooling holes of one of the flanges, and discharging the cooling fluid from the cooling holes of the other flange;

 (3) welding along the outer edge of the sealing faces of the two flanges to connect the two flanges into one body;

(4) discharging the cooling fluid after the welding is completed;

 (5) Fill the cooling tank with a sealant to fill the entire cooling tank. DRAWINGS

 BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic cross-sectional view of a preferred embodiment of a flange of the present invention.

 2 is a schematic cross-sectional view of another preferred embodiment of the flange of the present invention.

 Figure 3 is a perspective schematic view of a preferred embodiment of the conduit of the present invention.

 Figure 4 is a schematic illustration of a preferred embodiment of the pipe joining method of the present invention.

 Fig. 5 is a schematic view showing another preferred embodiment of the pipe joining method of the present invention, wherein the flange sealing surface is a concave-convex surface.

Figure 6 is a schematic view of another preferred embodiment of the pipe joining method of the present invention, wherein the flange sealing face is a gutter face type. detailed description DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. As shown in Fig. 1, the flange is provided with a cooling groove 4 on its sealing surface 8, and at least one cooling hole 9 is provided on the back surface 6 of the flange opposite to the sealing surface, through which the cooling hole 9 penetrates. And connected to the cooling tank 4.

 As shown in Fig. 2, in order to facilitate the welded connection between the flanges, it is preferable to provide the groove 5 at the outer edge of the flange sealing surface. In order to facilitate the perfusion of the cooling fluid, a cooling tube 10 may be connected to the cooling hole 9.

 The cooling grooves may be distributed only locally on the sealing surface or may be distributed over the entire sealing surface, either intermittently or continuously. In order to achieve uniform cooling and to facilitate the flow of the cooling fluid, it is preferred that the cooling trough form a continuous curve around the central bore of the flange.

 In a preferred embodiment, the cooling groove forms a curve such as a circular, spiral or other shape around the central bore of the flange. For ease of processing, the cooling bath preferably forms a closed circle.

 The invention does not have strict requirements on the cross-sectional shape of the cooling trough, and any conventional geometric shape can be used, such as semicircular, rectangular, semi-elliptical, triangular, trapezoidal, etc., or various irregular curved circumferences. Into the geometry. In a preferred embodiment, the cross-sectional shape of the cooling trough is selected from the group consisting of semicircular, rectangular and semi-elliptical. In view of the convenience of processing, and the influence on the strength and stress of the flange, it is more preferable that the cross-sectional shape is semicircular.

 The specific size of the cooling tank can be determined according to the requirements for blocking the conduction of welding heat to the inner wall of the pipe, the pressure requirements of the pipe, and the design requirements of the pipe strength.

 The location and number of cooling holes can be designed according to the need for the cooling fluid to block the conduction of welding heat toward the inner wall of the pipe and the requirement to uniformly inject the sealant. The requirements are selected. The flange of the present invention can be combined with another flange by welding and bonding, so that no bolt holes can be provided.

 The manufacture of the flange of the invention can be carried out in a processing workshop, or can be carried out at a pipeline construction site, preferably in a processing workshop, to facilitate the treatment of the inner coating, etc. Two or several flanges of the invention can be applied at the pipeline construction site. The groups are connected to any length.

The flange of the present invention can be made from any conventional flange in the art including, but not limited to, neck butt weld flanges, neck flat weld flanges, flat weld flanges, integral flanges or other types of methods. In a preferred embodiment, at least two cooling grooves may be provided on the sealing surface depending on the cooling requirements and the strength of the flange. In another preferred embodiment, a hollow tube of suitable length is attached to the opening of the cooling hole 9 at the back of the flange as a cooling tube 10, and the cooling tube is in communication with the cooling bath.

 As shown in Fig. 3, another preferred embodiment of the present invention provides a pipe comprising the flange of the present invention comprising a main pipe 1 and a flange 2. Wherein at least one end of the main pipe 1 is connected to the flange 2.

 Supervisors mainly refer to metal pipes, such as steel pipes, especially for large pipes used to transport materials, such as gas pipelines. According to the actual engineering needs, the material of the flange may be the same as or different from the material of the main pipe to which it is connected. In order to ensure the fluidity of the fluid in the pipe, it is preferred that the inner diameter of the flange be the same as the inner diameter of the pipe to which it is connected.

 The flange is connected to the main pipe by means of a splicing. In order to ensure the quality of the weld, the groove should be well drilled at the weld. After the above-mentioned main pipe is welded to the back or neck end of the flange, the inner surface of the main pipe and the flange is subjected to anticorrosive treatment by a method known in the art, and then the connection of the two flange joint structures is carried out. quasi. Among them, the concentricity of the main pipe and the flange is one of the key indicators affecting the quality of the joint. In order to ensure the coaxiality and parallelism of the main pipe and the flange, the equipment commonly used in the field, such as the field simple assembler and the pipe counterpart, can be used. Groups are paired.

 As shown in Figure 4, a further preferred embodiment of the present invention provides a method of joining a pipe comprising a flange of the present invention, comprising the steps of:

 (1) The sealing faces of the flanges 2 of the two pipes to be connected are coaxially butted, and the cooling grooves 4 of the two flanges are fitted to each other, and the adhesive 13 is applied at the sealing faces for bonding;

 (2) injecting a cooling fluid into the cooling bath 4 through the cooling hole 9 of one of the flanges, and discharging the cooling fluid from the cooling hole 9 of the other flange;

 (3) welding along the outer edge of the sealing faces of the two flanges to connect the two flanges into one body;

(4) The cooling fluid is discharged after the welding is completed and sufficiently cooled;

 (5) After the fluid to be cooled is sufficiently volatilized, the sealant is filled into the cooling tank 4 to fill the entire cooling tank.

 The cooling fluid used in the present invention may be various cooling fluid products that are commercially available, such as various gas or liquid products, preferably liquid coolants, more preferably water.

 In a preferred embodiment, the binder used is an elastomeric binder.

The sealant used in the present invention may be a sealant which is generally used in the market, and is preferably an epoxy resin which can satisfy the performance indexes shown in Table 1 below. _c

Epoxy resin mechanical properties requirements range

灌注密封剂的速度必须确保在密封剂操作时间内能够完成所需密封 剂量的灌注。

The rate at which the sealant is poured must ensure that the desired seal dose is filled during the sealant operating time.

 In order to further illustrate the materials and construction techniques of the present technology, the following examples are given. However, the examples are not to be construed as limiting the scope of the invention in any way. Example 1

 Material preparation

 (1) Select two seamless steel pipes with the specification of Φ133χ5 as the main pipe, and the surface of the butt joint of the two main pipes is processed into the groove.

 (2) As shown in Figure 2, make two identical neck-welded flanges with an inner diameter of 123 mm, an outer diameter of 250 mm and a flange thickness of 50 mm. Flange sealing surface 8 has a bevel 5 on the outer edge. The neck of the flange is 7 mm long, the flange neck is 5 mm thick, and the end of the neck is grooved. The flange sealing surface 8 is flat. The flange sealing surface 8 is provided with an annular cooling groove 4 having a semicircular cross section. The cooling channel is 12 mm wide and 6 mm deep. The cooling holes 9 of the connecting cooling groove 4 and the flange back 6 are 4 mm in diameter. A cooling tube 10 of 50 mm length is welded to the opening of the cooling hole 9 at the back of the flange.

 2. Pairing and connection of the main pipe and the flange

 As shown in Figure 3, a main pipe 1 and a flange 2 are paired. When pairing, pay special attention to the coaxiality between the main pipe and the flange. This step should strictly control the accuracy.

 After the pair is held, the welding of the neck portion of the main pipe and the flange is performed while maintaining the coaxiality, and the weld bead 12 is formed. After welding, a pipe component is formed, and the pipe component is composed of a main pipe and a flange.

3. Internal anti-corrosion treatment of the supervisor The inner surface of the main pipe of the pipe and the inner surface of the flange 3 are treated as required: Spray modified epoxy phenolic resin, thickness: 125-225 μιη. Among them, the primer and the topcoat are respectively subjected to thickness detection and appearance inspection. After curing, the next step can be carried out after passing the leak detection.

 The combination of the main pipe and the flange is carried out in the tooling workshop for welding and internal corrosion protection.

 4. Docking and bonding of pipe components

 As shown in Fig. 4, the two pipeline components that have undergone internal anti-corrosion treatment are paired, and the adhesive seal 13 is applied on the flange sealing surfaces of the two pipeline components, and then Beijing Union Titanium Adhesive Co., Ltd. is selected here. The product is cold-welded ΑΒ3602 (shear strength 25 MPa) as a bonding agent, and the cooking time is 5 minutes. After about 4 hours, the adhesive is completely cured before the next process can be carried out. When docking the two flanges, the position of the cooling tubes 10 on the two flanges is offset by a circumferential angle of 180 degrees.

 5. Welded connection of two flanges

 The cooling fluid is poured into the cooling bath 4 through the cooling pipe 10 on the flange. In the case where the cooling fluid flows normally, circumferential welding is performed along the outer edges of the two flange sealing faces to form the weld bead 11.

 6. Infusion sealant

One cooling hole on the combined pipe joint component is located below the pipe, and the other hole is located above the pipe, so that the hole located below is used as the pouring hole, and the hole located above is used as the vent hole. The sealant is poured into the cooling bath 4 by a manual pump through a cooling pipe 10 welded to the pouring hole. Epoxy resin is used here as a sealant. The epoxy resin is JX-1 epoxy resin produced by China National Water Resources and Hydropower Engineering Bureau (compressive strength: 54.3 MPa; adhesive strength: 3.5 N/mm ² ; compressive elastic modulus: 4.6 Gpa; viscosity: 9.8 mPa.s), the operation time is 90 minutes, until the cooling fluid tube welded on the vent hole above overflows the epoxy resin, stopping the perfusion.

 After 7 days, the epoxy resin was completely cured. The cooling tube on the flange is cut off, and the holes are sealed with screws to make the inner coating continuous pipe joint of the invention.

 7. Performance test of pipe flange joint structure

The inner coating continuous pipe flange joint structure prepared in this embodiment is subjected to a full-scale physical blasting test according to a conventional method in the art, and the two ends are welded by an elliptical steel head, and two diameters of the pipe are respectively drilled by Φ20, 27 The round hole of about mm is welded with two 120 mm bar pipe joints of 120 mm long as the vent hole and the water inlet hole, and the water inlet joint thread ruler Inch M27xl.5; vent joint thread size M20xl.5.

 After the sample is filled with water, the pressure is gradually increased. The pressurization process is as follows: First, pressurize the sample to 3 MPa, then hold the pressure for 10 minutes; then pressurize to 4 MPa, then hold the pressure for 10 minutes, further pressurize according to each stage 1.0 MPa, and hold 10 pressures per stage. Minutes, boost to 20 MPa, stop the test.

 During the test, the flange joint structure did not appear to be any abnormal. Example 2

 Referring to Fig. 5, this embodiment is basically the same as the above-described embodiment 1, except that the sealing surface of the flange is a concave-convex sealing surface. The advantage of this solution is the increased sealing capacity of the main pipe. Example 3

 Referring to Fig. 6, this embodiment is basically the same as the above-described embodiment 1, except that the sealing surface is a grooved surface sealing surface. The advantage of this solution is that the quality of the flange joint structure is improved and the sealing capacity of the main pipe is improved.

 Some preferred embodiments of the invention have been exemplarily described above. It will be understood by those skilled in the art that various equivalents and modifications may be made without departing from the spirit and scope of the invention. The technical solution thus obtained should also fall within the scope of the invention.

Claims

Rights request A flange characterized in that a cooling groove (4) is provided on a sealing surface (8) of the flange, and is provided on a back surface (6) of the flange opposite to the sealing surface There is at least one cooling hole (9) that penetrates the flange and communicates with the cooling groove (4).  2. The flange according to claim 1, wherein a shape of a center hole of the cooling groove (4) surrounding the flange is selected from a circular or spiral curved shape.  The flange according to claim 1 or 2, wherein the cooling groove (4) has a cross-sectional shape selected from a semicircular shape, a rectangular shape or a semi-elliptical shape.  The flange according to any one of claims 1 to 3, wherein the sealing surface (8) of the flange is selected from the group consisting of a flat surface, a concave-convex surface, a grooved surface surface or a ring connection surface type. Sealed form. A flange according to any one of claims 1 to 4, wherein the outer edge of the sealing surface ( ⁸ ) of the flange is provided with a groove ( ⁵ ).  6. A flange according to any one of claims 1-5, wherein the flange is selected from a neck butt weld flange, a neck flat weld flange, a plate flat weld flange or an integral flange.  A pipe comprising a main pipe (1), wherein at least one end of the main pipe (1) is connected to the flange according to any one of claims 1-6.  8. The pipe of claim 7, wherein the inner surface of the pipe is coated with a corrosion resistant inner coating.  9. A method of connecting pipes, comprising the steps of:  (1) connecting at least one end of a main pipe constituting the pipe to the flange according to any one of claims 1-6;  (2) coaxially butt the sealing faces (8) of the two main flanges to be joined, and apply adhesive at the sealing surface (8) for bonding;  (3) Inject cooling fluid into the cooling tank (4) through the cooling hole (9) of one of the flanges, and discharge the cooling fluid from the cooling hole (9) of the other flange;  (4) Welding along the outer edges of the sealing faces (8) of the two flanges to connect the two flanges into one body; (5) discharging the cooling fluid after the welding is completed; (6) Fill the cooling tank with a sealant to fill the entire cooling tank.  10. Method according to claim 9, wherein a pretensioning force is applied to the two flanges using a clamp when the sealing faces (8) of the flanges are coaxially butted.  11. The method of claim 9, wherein the inner surface of the main tube is coated with a corrosion resistant inner coating.  12. The method according to claim 11, wherein, after the step (1), before the step (2), the inner surface of the main pipe and the flange are subjected to an anticorrosive treatment.